WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.
0491990 321070 Mandrel MW
NOTE:
(Drift) For radial seal ring of the outer steering sector shaft on steering box [released]